Internal combustion engines may be operated in several modes including user controlled, torque governed, and all speed governed. User controlled is the most common mode where the user operates a foot pedal to request an amount of torque that the engine will generate. Increasing the requested torque generally causes an increase in the engine speed. User control relies upon the user to adjust the requested torque to account for variations in the loading upon the engine.
In conjunction with the user controlled mode, current efforts utilize gauging the lock up status of a torque converter to automatically determine the use of an appropriate governor. Governors, such as an all speed governor and a torque governor provide different limits on the torque an engine will generate. However, using the approach of choosing the appropriate governor based on lock up status of the torque converter results in a phenomenon in which the vehicle speed suddenly increases after the torque converter is switched from an unconnected state to a connected state. A locked up torque converter is beneficial for a work vehicle where it generally provides better fuel economy during transport of material and more torque or speed when climbing inclines. However, operators typically manually inhibit the torque converter to engage in a lockup mode because it results in an uncomfortable jolt. Turning off the ability for a torque converter to function in a locked up mode results in reduced fuel economy and inefficiencies in the drive.
Therein lies a need for an alternative approach for the governor functions of the engine to eliminate or reduce the sudden jolt factor.